Antibacterial effect of kitchen herbs against pathogenic multidrug-resistant E. coli isolates from calf diarrhoea.

Calf diarrhoea remains the biggest challenge both in the small and large farms. Infectious diarrhoea is associated with many pathogens, Escherichia coli being one, but majority are systematically treated with antibiotics. Since antimicrobial resistance (AMR) is a growing menace, the need to find alternative prophylactic solutions using popular kitchen herbs such as Trachyspermum ammi (carom seeds), Curcuma longa (turmeric) and cinnamon (Cinnamomum sp.) extracts is been investigated against virulent form of E. coli isolated from calf diarrhoea. The virulence factors identified in these isolates were ST (32.5%), LT (20%), eaeA (15%), stx1 (2.5%) and stx2 (5%) with the occurrence of the most common serogroups as O18 (15%) followed by O111 (12.5%). Highest resistance was seen with beta lactam + beta lactamase inhibitor (amoxicillin/clavulanic acid) followed by beta lactams (ampicillin, cefuroxime and cefepime). The zone of inhibition due to cinnamon (methanol) and carom seed (ethanol) extracts (500 to 250 µg/mL concentration) on E. coli bacteria was >19 mm, respectively. Turmeric, cinnamon and carom had the potency of inhibiting the pathogenic E. coli which maybe suggestive of its use in calf diets as prophylaxis against diarrhoea.

Diagnosis of mixed gastrointestinal nematode infection in goat by an indirect-ELISA.

An indirect-ELISA for the diagnosis of mixed gastrointestinal (GI) nematode infection comprising Oesophagostomum, Haemonchus and Trichuris species was standardized using crude somatic antigen of Oesophagostomum columbianum (CSAg-Oc) and sera of slaughtered goats with known parasitological status including Oesophagostomum, Haemonchus, and Trichuris (strong positive), Haemonchus and Trichuris (weak positive) and parasite free goats (negative). Two cut-off points, i.e. higher and lower cut-off were determined using the strong positive, weak positive and the negative control sera of goats. Thus the test sera having optical density (OD) values greater than the higher cut-off were considered positive for mixed infection with all the three nematode species, intermediate between the higher and the lower cut-off values were considered positive for mixed infection of Haemonchus and Trichuris, and less than the lower cut-off value were considered negative for any of these three nematode species. The sensitivity, specificity and accuracy of the ELISA for diagnosis of mixed GI nematodoses were 81.25, 93.18% and 90.00%, respectively, while it was 92.86% sensitive, 75.00% specific and 91.67% accurate for the diagnosis of mixed infection with Haemonchus and Trichuris. The ELISA, so standardized, detected 27.78% sero-prevalence of Oesophagostomum plus Haemonchus and Trichuris infection and 38.89% percent of Haemonchus and Trichuris infection in the field goats. The standardized assay might be exploited as a diagnostic tool and also for sero-epidemiological study of two important GI nematodes of goats.

Changes in the haemato-biochemical pattern due to experimentally induced haemonchosis in Sahabadi sheep.

The study evaluated the damage caused by Haemonchus contortus in terms of blood loss, faecal clearance of plasma protein and elevated serum enzyme activity in Sahabadi sheep. Apparently healthy Sahabadi sheep (n = 15) were selected randomly based on phenotypic characteristics and divided into two groups; infected (n = 8) and uninfected control (n = 6) and one sheep was used as donor animal. Each animal of infected group were orally infected with 700 third stage larvae (L3) of H. contortus/kg body weight. Blood from all the fourteen animals were collected at weekly intervals starting from day one to 42 day post infection. Parameters studied were haemoglobin concentration (Hb), packed cell volume (PCV), total erythrocyte count (TEC), total serum protein, serum albumin, serum globulin, alkaline phosphatase, Alanine amino transferase and Aspartate amino transferase. Statistical analysis showed that significant decreases in Hb, PCV, TEC and serum protein concentration and significant increases in serum enzymes level in infected sheep compared to uninfected control. The present study concluded that experimental H. contortus infection caused disturbances to the haemopoietic system resulting anaemia and severe damage to abomasal mucosa resulting lower serum protein and higher enzyme activities.

Polyclonal antibody based coproantigen detection immunoassay for diagnosis of Oesophagostomum columbianum infection in goats.

A polyclonal antibody based coproantigen detection enzyme linked immunosorbent assay (cAg-ELISA) for diagnosis of experimental and natural Oesophagostomum columbianum infection in goats was developed and evaluated. Adult O. columbianum worms, collected from the caecum and colon of slaughtered goats, were triturated and cultured for obtaining infective third stage larvae (L(3)) and also used for preparation of excretory-secretory antigen (ESAg). Experimental goats were orally infected each with 600 L(3)/kg of the body weight. Filter sterilized faecal supernatant, i.e. the coproantigen (cAg) was harvested from the rectal faeces of all the infected goats, on alternate days from day-5 till day-31 after the infection. Hyperimmune serum (HIS) against ESAg of O. columbianum was raised in rabbits. Molecular and antigenic characterization of ES products of O. columbianum by HIS revealed that 50 and 39kDa polypeptides were immuno-dominant. Coproantigen detection ELISA was standardized by using the cAg as coating antigen and its subsequent binding with the HIS against ESAg of O. columbianum. The sensitivity, specificity and accuracy of the standardized assay were determined by evaluating the assay on the faecal supernatant of 96 slaughtered goats taking into consideration their recorded parasitological status in respect of the abomasal and the intestinal parasites. The cAg-ELISA detected the prepatent oesophagostomosis on 20-24-day-post-infection with a sensitivity, specificity and accuracy of 88, 89.13 and 88.54%, respectively. The assay is relatively easy to perform and would serve as a reliable tool for detection of caprine nodular oesophagostomosis.